/*
 * librdkafka - Apache Kafka C library
 *
 * Copyright (c) 2019 Magnus Edenhill
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef _RDKAFKA_COORD_H_
#define _RDKAFKA_COORD_H_


typedef TAILQ_HEAD(rd_kafka_coord_cache_head_s, rd_kafka_coord_cache_entry_s)
        rd_kafka_coord_cache_head_t;

/**
 * @brief Coordinator cache entry
 */
typedef struct rd_kafka_coord_cache_entry_s {
        TAILQ_ENTRY(rd_kafka_coord_cache_entry_s) cce_link;
        rd_kafka_coordtype_t cce_coordtype; /**< Coordinator type */
        char                *cce_coordkey;  /**< Coordinator type key,
                                             *   e.g the group id */
        rd_ts_t              cce_ts_used;   /**< Last used timestamp */
        rd_kafka_broker_t   *cce_rkb;       /**< The cached coordinator */

} rd_kafka_coord_cache_entry_t;

/**
 * @brief Coordinator cache
 */
typedef struct rd_kafka_coord_cache_s {
        rd_kafka_coord_cache_head_t cc_entries;      /**< Cache entries */
        int                         cc_cnt;          /**< Number of entries */
        rd_ts_t                     cc_expire_thres; /**< Entries not used in
                                                      *   this long will be
                                                      *   expired */
} rd_kafka_coord_cache_t;


void rd_kafka_coord_cache_expire (rd_kafka_coord_cache_t *cc);
void rd_kafka_coord_cache_evict (rd_kafka_coord_cache_t *cc,
                                 rd_kafka_broker_t *rkb);
void rd_kafka_coord_cache_destroy (rd_kafka_coord_cache_t *cc);
void rd_kafka_coord_cache_init (rd_kafka_coord_cache_t *cc,
                                int expire_thres_ms);




/**
 * @name Coordinator requests
 */

/**
 * @brief Request to be sent to coordinator.
 *        Includes looking up, caching, and connecting to, the coordinator.
 */
typedef struct rd_kafka_coord_req_s {
        TAILQ_ENTRY(rd_kafka_coord_req_s) creq_link; /**< rk_coord_reqs */
        rd_kafka_coordtype_t creq_coordtype; /**< Coordinator type */
        char                *creq_coordkey;  /**< Coordinator key */

        rd_kafka_op_t *creq_rko;             /**< Requester's rko that is
                                              *   provided as opaque on
                                              *   to creq_resp_cb. */
        rd_ts_t        creq_ts_timeout;      /**< Absolute timeout.
                                              *   Will fail with an error
                                              *   code pertaining to the
                                              *   current state */

        rd_kafka_send_req_cb_t *creq_send_req_cb; /**< Sender callback */

        rd_kafka_replyq_t   creq_replyq;     /**< Reply queue */
        rd_kafka_resp_cb_t *creq_resp_cb;    /**< Reply queue response
                                              *   parsing callback for the
                                              *   request sent by
                                              *   send_req_cb */
        void               *creq_reply_opaque; /**< Opaque passed to
                                                *   resp_cb */

        int                 creq_refcnt;     /**< Internal reply queue for
                                              *   FindCoordinator requests
                                              *   which is forwarded to the
                                              *   rk_ops queue, but allows
                                              *   destroying the creq even
                                              *   with outstanding
                                              *   FindCoordinator requests. */
} rd_kafka_coord_req_t;


void rd_kafka_coord_req (rd_kafka_t *rk,
                         rd_kafka_coordtype_t coordtype,
                         const char *coordkey,
                         rd_kafka_send_req_cb_t *send_req_cb,
                         rd_kafka_op_t *rko,
                         int timeout_ms,
                         rd_kafka_replyq_t replyq,
                         rd_kafka_resp_cb_t *resp_cb,
                         void *reply_opaque);

void rd_kafka_coord_rkb_monitor_cb (rd_kafka_broker_t *rkb);

void rd_kafka_coord_reqs_term (rd_kafka_t *rk);
void rd_kafka_coord_reqs_init (rd_kafka_t *rk);
#endif /* _RDKAFKA_COORD_H_ */
